- refactor most files into packages. provide a degree of

backwards compat for major import targets.  command and config
are too front-facing for a move like this so leave them
as is.  first part of #302

41 files changed, 305 insertions, 269 deletions

diff --git a/.gitignore b/.gitignore
index 0875618..5a97f5e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@ alembic.ini
 .coverage
 coverage.xml
 .tox
+*.patch
diff --git a/alembic/__init__.py b/alembic/__init__.py
index f429441..345bf26 100644
--- a/alembic/__init__.py
+++ b/alembic/__init__.py
@@ -1,9 +1,15 @@
 from os import path
 
-__version__ = '0.7.7'
+__version__ = '0.8.0'
 
 package_dir = path.abspath(path.dirname(__file__))
 
 
 from . import op  # noqa
 from . import context  # noqa
+
+import sys
+from .runtime import environment
+from .runtime import migration
+sys.modules['alembic.migration'] = migration
+sys.modules['alembic.environment'] = environment
diff --git a/alembic/autogenerate/api.py b/alembic/autogenerate/api.py
index 6281a6c..e912a5d 100644
--- a/alembic/autogenerate/api.py
+++ b/alembic/autogenerate/api.py
@@ -5,7 +5,7 @@ import logging
 import itertools
 import re
 
-from ..compat import StringIO
+from ..util.compat import StringIO
 
 from mako.pygen import PythonPrinter
 from sqlalchemy.engine.reflection import Inspector
diff --git a/alembic/autogenerate/compare.py b/alembic/autogenerate/compare.py
index 2aae962..9c04f80 100644
--- a/alembic/autogenerate/compare.py
+++ b/alembic/autogenerate/compare.py
@@ -1,7 +1,7 @@
 from sqlalchemy import schema as sa_schema, types as sqltypes
 from sqlalchemy import event
 import logging
-from .. import compat
+from ..util import compat
 from sqlalchemy.util import OrderedSet
 import re
 from .render import _user_defined_render
diff --git a/alembic/autogenerate/render.py b/alembic/autogenerate/render.py
index 5007652..82f348b 100644
--- a/alembic/autogenerate/render.py
+++ b/alembic/autogenerate/render.py
@@ -1,9 +1,9 @@
 from sqlalchemy import schema as sa_schema, types as sqltypes, sql
 import logging
-from .. import compat
+from ..util import compat
 from ..ddl.base import _table_for_constraint, _fk_spec
 import re
-from ..compat import string_types
+from ..util.compat import string_types
 
 log = logging.getLogger(__name__)
 
diff --git a/alembic/command.py b/alembic/command.py
index 5ba6d6a..fc80e38 100644
--- a/alembic/command.py
+++ b/alembic/command.py
@@ -1,8 +1,9 @@
 import os
 
 from .script import ScriptDirectory
-from .environment import EnvironmentContext
-from . import util, autogenerate as autogen
+from .runtime.environment import EnvironmentContext
+from . import util
+from . import autogenerate as autogen
 
 
 def list_templates(config):
diff --git a/alembic/config.py b/alembic/config.py
index 7f813d2..74b4d17 100644
--- a/alembic/config.py
+++ b/alembic/config.py
@@ -1,10 +1,13 @@
 from argparse import ArgumentParser
-from .compat import SafeConfigParser
+from .util.compat import SafeConfigParser
 import inspect
 import os
 import sys
 
-from . import command, util, package_dir, compat
+from . import command
+from . import util
+from . import package_dir
+from .util import compat
 
 
 class Config(object):
diff --git a/alembic/context.py b/alembic/context.py
index 9c0f676..1b1a3ab 100644
--- a/alembic/context.py
+++ b/alembic/context.py
@@ -1,4 +1,4 @@
-from .environment import EnvironmentContext
+from .runtime.environment import EnvironmentContext
 from . import util
 
 # create proxy functions for
diff --git a/alembic/ddl/impl.py b/alembic/ddl/impl.py
index 3cca1ef..8c4f1d6 100644
--- a/alembic/ddl/impl.py
+++ b/alembic/ddl/impl.py
@@ -3,7 +3,7 @@ from sqlalchemy.ext.compiler import compiles
 from sqlalchemy import schema, text, sql
 from sqlalchemy import types as sqltypes
 
-from ..compat import string_types, text_type, with_metaclass
+from ..util.compat import string_types, text_type, with_metaclass
 from .. import util
 from . import base
 
diff --git a/alembic/ddl/mysql.py b/alembic/ddl/mysql.py
index 7956185..fe42145 100644
--- a/alembic/ddl/mysql.py
+++ b/alembic/ddl/mysql.py
@@ -2,7 +2,7 @@ from sqlalchemy.ext.compiler import compiles
 from sqlalchemy import types as sqltypes
 from sqlalchemy import schema
 
-from ..compat import string_types
+from ..util.compat import string_types
 from .. import util
 from .impl import DefaultImpl
 from .base import ColumnNullable, ColumnName, ColumnDefault, \
diff --git a/alembic/ddl/postgresql.py b/alembic/ddl/postgresql.py
index 9f97b34..ea423d7 100644
--- a/alembic/ddl/postgresql.py
+++ b/alembic/ddl/postgresql.py
@@ -1,6 +1,6 @@
 import re
 
-from .. import compat
+from ..util import compat
 from .. import util
 from .base import compiles, alter_table, format_table_name, RenameTable
 from .impl import DefaultImpl
diff --git a/alembic/op.py b/alembic/op.py
index 8e5f777..615fd58 100644
--- a/alembic/op.py
+++ b/alembic/op.py
@@ -1,4 +1,4 @@
-from .operations import Operations
+from .operations.base import Operations
 from . import util
 
 # create proxy functions for
diff --git a/alembic/operations/__init__.py b/alembic/operations/__init__.py
new file mode 100644
index 0000000..d7902ea
--- /dev/null
+++ b/alembic/operations/__init__.py
@@ -0,0 +1,3 @@
+from .base import Operations, BatchOperations  # noqa
+
+__all__ = ['Operations', 'BatchOperations']
\ No newline at end of file
diff --git a/alembic/operations.py b/alembic/operations/base.py
index 2bf8060..cda5aa2 100644
--- a/alembic/operations.py
+++ b/alembic/operations/base.py
@@ -3,9 +3,10 @@ from contextlib import contextmanager
 from sqlalchemy.types import NULLTYPE, Integer
 from sqlalchemy import schema as sa_schema
 
-from . import util, batch
-from .compat import string_types
-from .ddl import impl
+from .. import util
+from . import batch
+from ..util.compat import string_types
+from ..ddl import impl
 
 __all__ = ('Operations', 'BatchOperations')
 
@@ -58,7 +59,7 @@ class Operations(object):
     @classmethod
     @contextmanager
     def context(cls, migration_context):
-        from .op import _install_proxy, _remove_proxy
+        from ..op import _install_proxy, _remove_proxy
         op = Operations(migration_context)
         _install_proxy(op)
         yield op
diff --git a/alembic/batch.py b/alembic/operations/batch.py
index 1006739..9644a33 100644
--- a/alembic/batch.py
+++ b/alembic/operations/batch.py
@@ -3,8 +3,8 @@ from sqlalchemy import Table, MetaData, Index, select, Column, \
 from sqlalchemy import types as sqltypes
 from sqlalchemy import schema as sql_schema
 from sqlalchemy.util import OrderedDict
-from . import util
-from .ddl.base import _columns_for_constraint, _is_type_bound
+from .. import util
+from ..ddl.base import _columns_for_constraint, _is_type_bound
 
 
 class BatchOperationsImpl(object):
diff --git a/alembic/runtime/__init__.py b/alembic/runtime/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/alembic/runtime/__init__.py
diff --git a/alembic/environment.py b/alembic/runtime/environment.py
index 860315b..287d70a 100644
--- a/alembic/environment.py
+++ b/alembic/runtime/environment.py
@@ -1,6 +1,6 @@
-from .operations import Operations
+from ..operations import Operations
 from .migration import MigrationContext
-from . import util
+from .. import util
 
 
 class EnvironmentContext(object):
@@ -96,12 +96,12 @@ class EnvironmentContext(object):
         be made available as ``from alembic import context``.
 
         """
-        from .context import _install_proxy
+        from ..context import _install_proxy
         _install_proxy(self)
         return self
 
     def __exit__(self, *arg, **kw):
-        from . import context, op
+        from .. import context, op
         context._remove_proxy()
         op._remove_proxy()
 
diff --git a/alembic/migration.py b/alembic/runtime/migration.py
index 9b46052..84a3c7f 100644
--- a/alembic/migration.py
+++ b/alembic/runtime/migration.py
@@ -6,8 +6,8 @@ from sqlalchemy import MetaData, Table, Column, String, literal_column
 from sqlalchemy.engine.strategies import MockEngineStrategy
 from sqlalchemy.engine import url as sqla_url
 
-from .compat import callable, EncodedIO
-from . import ddl, util
+from ..util.compat import callable, EncodedIO
+from .. import ddl, util
 
 log = logging.getLogger(__name__)
 
diff --git a/alembic/script/__init__.py b/alembic/script/__init__.py
new file mode 100644
index 0000000..cae294f
--- /dev/null
+++ b/alembic/script/__init__.py
@@ -0,0 +1,3 @@
+from .base import ScriptDirectory, Script  # noqa
+
+__all__ = ['ScriptDirectory', 'Script']
diff --git a/alembic/script.py b/alembic/script/base.py
index 095a04b..e30c8b2 100644
--- a/alembic/script.py
+++ b/alembic/script/base.py
@@ -2,10 +2,10 @@ import datetime
 import os
 import re
 import shutil
-from . import util
-from . import compat
+from .. import util
+from ..util import compat
 from . import revision
-from . import migration
+from ..runtime import migration
 
 from contextlib import contextmanager
 
diff --git a/alembic/revision.py b/alembic/script/revision.py
index 4eea514..e9958b1 100644
--- a/alembic/revision.py
+++ b/alembic/script/revision.py
@@ -1,10 +1,9 @@
 import re
 import collections
-import itertools
 
-from . import util
+from .. import util
 from sqlalchemy import util as sqlautil
-from . import compat
+from ..util import compat
 
 _relative_destination = re.compile(r'(?:(.+?)@)?(\w+)?((?:\+|-)\d+)')
 
diff --git a/alembic/testing/assertions.py b/alembic/testing/assertions.py
index b3a5acd..6acca21 100644
--- a/alembic/testing/assertions.py
+++ b/alembic/testing/assertions.py
@@ -2,9 +2,9 @@ from __future__ import absolute_import
 
 
 import re
-from alembic import util
+from .. import util
 from sqlalchemy.engine import default
-from alembic.compat import text_type, py3k
+from ..util.compat import text_type, py3k
 import contextlib
 from sqlalchemy.util import decorator
 from sqlalchemy import exc as sa_exc
diff --git a/alembic/testing/env.py b/alembic/testing/env.py
index 9c53d5d..f8ad447 100644
--- a/alembic/testing/env.py
+++ b/alembic/testing/env.py
@@ -4,9 +4,9 @@ import os
 import shutil
 import textwrap
 
-from alembic.compat import u
-from alembic.script import Script, ScriptDirectory
-from alembic import util
+from ..util.compat import u
+from ..script import Script, ScriptDirectory
+from .. import util
 from . import engines
 from . import provision
 
diff --git a/alembic/testing/exclusions.py b/alembic/testing/exclusions.py
index 88df9fc..90f8bc6 100644
--- a/alembic/testing/exclusions.py
+++ b/alembic/testing/exclusions.py
@@ -14,11 +14,12 @@ from .plugin.plugin_base import SkipTest
 from sqlalchemy.util import decorator
 from . import config
 from sqlalchemy import util
-from alembic import compat
+from ..util import compat
 import inspect
 import contextlib
 from .compat import get_url_driver_name, get_url_backend_name
 
+
 def skip_if(predicate, reason=None):
     rule = compound()
     pred = _as_predicate(predicate, reason)
diff --git a/alembic/testing/fixtures.py b/alembic/testing/fixtures.py
index ae25fd2..7e05525 100644
--- a/alembic/testing/fixtures.py
+++ b/alembic/testing/fixtures.py
@@ -5,13 +5,12 @@ import re
 from sqlalchemy import create_engine, text, MetaData
 
 import alembic
-from alembic.compat import configparser
-from alembic import util
-from alembic.compat import string_types, text_type
-from alembic.migration import MigrationContext
-from alembic.environment import EnvironmentContext
-from alembic.operations import Operations
-from alembic.ddl.impl import _impls
+from ..util.compat import configparser
+from .. import util
+from ..util.compat import string_types, text_type
+from ..migration import MigrationContext
+from ..environment import EnvironmentContext
+from ..operations import Operations
 from contextlib import contextmanager
 from .plugin.plugin_base import SkipTest
 from .assertions import _get_dialect, eq_
diff --git a/alembic/testing/mock.py b/alembic/testing/mock.py
index cdfcb88..b82a404 100644
--- a/alembic/testing/mock.py
+++ b/alembic/testing/mock.py
@@ -12,7 +12,7 @@
 
 """
 from __future__ import absolute_import
-from alembic.compat import py33
+from ..util.compat import py33
 
 if py33:
     from unittest.mock import MagicMock, Mock, call, patch
diff --git a/alembic/testing/provision.py b/alembic/testing/provision.py
index 801d36b..37ae141 100644
--- a/alembic/testing/provision.py
+++ b/alembic/testing/provision.py
@@ -3,9 +3,9 @@
 """
 from sqlalchemy.engine import url as sa_url
 from sqlalchemy import text
-from alembic import compat
-from alembic.testing import config, engines
-from alembic.testing.compat import get_url_backend_name
+from ..util import compat
+from . import config, engines
+from .compat import get_url_backend_name
 
 FOLLOWER_IDENT = None
 
diff --git a/alembic/util/__init__.py b/alembic/util/__init__.py
new file mode 100644
index 0000000..6cfc5d3
--- /dev/null
+++ b/alembic/util/__init__.py
@@ -0,0 +1,20 @@
+from .langhelpers import (  # noqa
+    create_module_class_proxy, asbool, rev_id, to_tuple, memoized_property,
+    immutabledict, _with_legacy_names)
+from .messaging import (  # noqa
+    write_outstream, status, err, obfuscate_url_pw, warn, msg, format_as_comma)
+from .pyfiles import (  # noqa
+    template_to_file, coerce_resource_to_filename, simple_pyc_file_from_path,
+    pyc_file_from_path, load_python_file)
+from .sqla_compat import (  # noqa
+    sqla_07, sqla_079, sqla_08, sqla_083, sqla_084, sqla_09, sqla_092,
+    sqla_094, sqla_094, sqla_099, sqla_100, sqla_105)
+
+
+class CommandError(Exception):
+    pass
+
+
+if not sqla_07:
+    raise CommandError(
+        "SQLAlchemy 0.7.3 or greater is required. ")
diff --git a/alembic/compat.py b/alembic/util/compat.py
index a9e35f0..a9e35f0 100644
--- a/alembic/compat.py
+++ b/alembic/util/compat.py
diff --git a/alembic/util.py b/alembic/util/langhelpers.py
index 2e0f731..04cb6e4 100644
--- a/alembic/util.py
+++ b/alembic/util/langhelpers.py
@@ -1,78 +1,14 @@
-import sys
-import os
 import textwrap
 import warnings
-import re
 import inspect
 import uuid
 import collections
 
-from mako.template import Template
-from sqlalchemy.engine import url
-from sqlalchemy import __version__
-
-from .compat import callable, exec_, load_module_py, load_module_pyc, \
-    binary_type, string_types, py27
-
-
-class CommandError(Exception):
-    pass
-
-
-def _safe_int(value):
-    try:
-        return int(value)
-    except:
-        return value
-_vers = tuple(
-    [_safe_int(x) for x in re.findall(r'(\d+|[abc]\d)', __version__)])
-sqla_07 = _vers > (0, 7, 2)
-sqla_079 = _vers >= (0, 7, 9)
-sqla_08 = _vers >= (0, 8, 0)
-sqla_083 = _vers >= (0, 8, 3)
-sqla_084 = _vers >= (0, 8, 4)
-sqla_09 = _vers >= (0, 9, 0)
-sqla_092 = _vers >= (0, 9, 2)
-sqla_094 = _vers >= (0, 9, 4)
-sqla_094 = _vers >= (0, 9, 4)
-sqla_099 = _vers >= (0, 9, 9)
-sqla_100 = _vers >= (1, 0, 0)
-sqla_105 = _vers >= (1, 0, 5)
-if not sqla_07:
-    raise CommandError(
-        "SQLAlchemy 0.7.3 or greater is required. ")
+from .compat import callable, exec_, string_types
 
 from sqlalchemy.util import format_argspec_plus, update_wrapper
 from sqlalchemy.util.compat import inspect_getfullargspec
 
-import logging
-log = logging.getLogger(__name__)
-
-if py27:
-    # disable "no handler found" errors
-    logging.getLogger('alembic').addHandler(logging.NullHandler())
-
-
-try:
-    import fcntl
-    import termios
-    import struct
-    ioctl = fcntl.ioctl(0, termios.TIOCGWINSZ,
-                        struct.pack('HHHH', 0, 0, 0, 0))
-    _h, TERMWIDTH, _hp, _wp = struct.unpack('HHHH', ioctl)
-    if TERMWIDTH <= 0:  # can occur if running in emacs pseudo-tty
-        TERMWIDTH = None
-except (ImportError, IOError):
-    TERMWIDTH = None
-
-
-def template_to_file(template_file, dest, output_encoding, **kw):
-    with open(dest, 'wb') as f:
-        template = Template(filename=template_file)
-        f.write(
-            template.render_unicode(**kw).encode(output_encoding)
-        )
-
 
 def create_module_class_proxy(cls, globals_, locals_):
     """Create module level proxy functions for the
@@ -157,135 +93,11 @@ def create_module_class_proxy(cls, globals_, locals_):
                 attr_names.add(methname)
 
 
-def write_outstream(stream, *text):
-    encoding = getattr(stream, 'encoding', 'ascii') or 'ascii'
-    for t in text:
-        if not isinstance(t, binary_type):
-            t = t.encode(encoding, 'replace')
-        t = t.decode(encoding)
-        try:
-            stream.write(t)
-        except IOError:
-            # suppress "broken pipe" errors.
-            # no known way to handle this on Python 3 however
-            # as the exception is "ignored" (noisily) in TextIOWrapper.
-            break
-
-
-def coerce_resource_to_filename(fname):
-    """Interpret a filename as either a filesystem location or as a package
-    resource.
-
-    Names that are non absolute paths and contain a colon
-    are interpreted as resources and coerced to a file location.
-
-    """
-    if not os.path.isabs(fname) and ":" in fname:
-        import pkg_resources
-        fname = pkg_resources.resource_filename(*fname.split(':'))
-    return fname
-
-
-def status(_statmsg, fn, *arg, **kw):
-    msg(_statmsg + " ...", False)
-    try:
-        ret = fn(*arg, **kw)
-        write_outstream(sys.stdout, " done\n")
-        return ret
-    except:
-        write_outstream(sys.stdout, " FAILED\n")
-        raise
-
-
-def err(message):
-    log.error(message)
-    msg("FAILED: %s" % message)
-    sys.exit(-1)
-
-
-def obfuscate_url_pw(u):
-    u = url.make_url(u)
-    if u.password:
-        u.password = 'XXXXX'
-    return str(u)
-
-
 def asbool(value):
     return value is not None and \
         value.lower() == 'true'
 
 
-def warn(msg):
-    warnings.warn(msg)
-
-
-def msg(msg, newline=True):
-    if TERMWIDTH is None:
-        write_outstream(sys.stdout, msg)
-        if newline:
-            write_outstream(sys.stdout, "\n")
-    else:
-        # left indent output lines
-        lines = textwrap.wrap(msg, TERMWIDTH)
-        if len(lines) > 1:
-            for line in lines[0:-1]:
-                write_outstream(sys.stdout, "  ", line, "\n")
-        write_outstream(sys.stdout, "  ", lines[-1], ("\n" if newline else ""))
-
-
-def load_python_file(dir_, filename):
-    """Load a file from the given path as a Python module."""
-
-    module_id = re.sub(r'\W', "_", filename)
-    path = os.path.join(dir_, filename)
-    _, ext = os.path.splitext(filename)
-    if ext == ".py":
-        if os.path.exists(path):
-            module = load_module_py(module_id, path)
-        elif os.path.exists(simple_pyc_file_from_path(path)):
-            # look for sourceless load
-            module = load_module_pyc(
-                module_id, simple_pyc_file_from_path(path))
-        else:
-            raise ImportError("Can't find Python file %s" % path)
-    elif ext in (".pyc", ".pyo"):
-        module = load_module_pyc(module_id, path)
-    del sys.modules[module_id]
-    return module
-
-
-def simple_pyc_file_from_path(path):
-    """Given a python source path, return the so-called
-    "sourceless" .pyc or .pyo path.
-
-    This just a .pyc or .pyo file where the .py file would be.
-
-    Even with PEP-3147, which normally puts .pyc/.pyo files in __pycache__,
-    this use case remains supported as a so-called "sourceless module import".
-
-    """
-    if sys.flags.optimize:
-        return path + "o"  # e.g. .pyo
-    else:
-        return path + "c"  # e.g. .pyc
-
-
-def pyc_file_from_path(path):
-    """Given a python source path, locate the .pyc.
-
-    See http://www.python.org/dev/peps/pep-3147/
-                        #detecting-pep-3147-availability
-        http://www.python.org/dev/peps/pep-3147/#file-extension-checks
-
-    """
-    import imp
-    has3147 = hasattr(imp, 'get_tag')
-    if has3147:
-        return imp.cache_from_source(path)
-    else:
-        return simple_pyc_file_from_path(path)
-
-
 def rev_id():
     val = int(uuid.uuid4()) % 100000000000000
     return hex(val)[2:-1]
@@ -302,17 +114,6 @@ def to_tuple(x, default=None):
         raise ValueError("Don't know how to turn %r into a tuple" % x)
 
 
-def format_as_comma(value):
-    if value is None:
-        return ""
-    elif isinstance(value, string_types):
-        return value
-    elif isinstance(value, collections.Iterable):
-        return ", ".join(value)
-    else:
-        raise ValueError("Don't know how to comma-format %r" % value)
-
-
 class memoized_property(object):
 
     """A read-only @property that is only evaluated once."""
diff --git a/alembic/util/messaging.py b/alembic/util/messaging.py
new file mode 100644
index 0000000..c202e96
--- /dev/null
+++ b/alembic/util/messaging.py
@@ -0,0 +1,94 @@
+from .compat import py27, binary_type, string_types
+import sys
+from sqlalchemy.engine import url
+import warnings
+import textwrap
+import collections
+import logging
+
+log = logging.getLogger(__name__)
+
+if py27:
+    # disable "no handler found" errors
+    logging.getLogger('alembic').addHandler(logging.NullHandler())
+
+
+try:
+    import fcntl
+    import termios
+    import struct
+    ioctl = fcntl.ioctl(0, termios.TIOCGWINSZ,
+                        struct.pack('HHHH', 0, 0, 0, 0))
+    _h, TERMWIDTH, _hp, _wp = struct.unpack('HHHH', ioctl)
+    if TERMWIDTH <= 0:  # can occur if running in emacs pseudo-tty
+        TERMWIDTH = None
+except (ImportError, IOError):
+    TERMWIDTH = None
+
+
+def write_outstream(stream, *text):
+    encoding = getattr(stream, 'encoding', 'ascii') or 'ascii'
+    for t in text:
+        if not isinstance(t, binary_type):
+            t = t.encode(encoding, 'replace')
+        t = t.decode(encoding)
+        try:
+            stream.write(t)
+        except IOError:
+            # suppress "broken pipe" errors.
+            # no known way to handle this on Python 3 however
+            # as the exception is "ignored" (noisily) in TextIOWrapper.
+            break
+
+
+def status(_statmsg, fn, *arg, **kw):
+    msg(_statmsg + " ...", False)
+    try:
+        ret = fn(*arg, **kw)
+        write_outstream(sys.stdout, " done\n")
+        return ret
+    except:
+        write_outstream(sys.stdout, " FAILED\n")
+        raise
+
+
+def err(message):
+    log.error(message)
+    msg("FAILED: %s" % message)
+    sys.exit(-1)
+
+
+def obfuscate_url_pw(u):
+    u = url.make_url(u)
+    if u.password:
+        u.password = 'XXXXX'
+    return str(u)
+
+
+def warn(msg):
+    warnings.warn(msg)
+
+
+def msg(msg, newline=True):
+    if TERMWIDTH is None:
+        write_outstream(sys.stdout, msg)
+        if newline:
+            write_outstream(sys.stdout, "\n")
+    else:
+        # left indent output lines
+        lines = textwrap.wrap(msg, TERMWIDTH)
+        if len(lines) > 1:
+            for line in lines[0:-1]:
+                write_outstream(sys.stdout, "  ", line, "\n")
+        write_outstream(sys.stdout, "  ", lines[-1], ("\n" if newline else ""))
+
+
+def format_as_comma(value):
+    if value is None:
+        return ""
+    elif isinstance(value, string_types):
+        return value
+    elif isinstance(value, collections.Iterable):
+        return ", ".join(value)
+    else:
+        raise ValueError("Don't know how to comma-format %r" % value)
diff --git a/alembic/util/pyfiles.py b/alembic/util/pyfiles.py
new file mode 100644
index 0000000..c51e187
--- /dev/null
+++ b/alembic/util/pyfiles.py
@@ -0,0 +1,80 @@
+import sys
+import os
+import re
+from .compat import load_module_py, load_module_pyc
+from mako.template import Template
+
+
+def template_to_file(template_file, dest, output_encoding, **kw):
+    with open(dest, 'wb') as f:
+        template = Template(filename=template_file)
+        f.write(
+            template.render_unicode(**kw).encode(output_encoding)
+        )
+
+
+def coerce_resource_to_filename(fname):
+    """Interpret a filename as either a filesystem location or as a package
+    resource.
+
+    Names that are non absolute paths and contain a colon
+    are interpreted as resources and coerced to a file location.
+
+    """
+    if not os.path.isabs(fname) and ":" in fname:
+        import pkg_resources
+        fname = pkg_resources.resource_filename(*fname.split(':'))
+    return fname
+
+
+def simple_pyc_file_from_path(path):
+    """Given a python source path, return the so-called
+    "sourceless" .pyc or .pyo path.
+
+    This just a .pyc or .pyo file where the .py file would be.
+
+    Even with PEP-3147, which normally puts .pyc/.pyo files in __pycache__,
+    this use case remains supported as a so-called "sourceless module import".
+
+    """
+    if sys.flags.optimize:
+        return path + "o"  # e.g. .pyo
+    else:
+        return path + "c"  # e.g. .pyc
+
+
+def pyc_file_from_path(path):
+    """Given a python source path, locate the .pyc.
+
+    See http://www.python.org/dev/peps/pep-3147/
+                        #detecting-pep-3147-availability
+        http://www.python.org/dev/peps/pep-3147/#file-extension-checks
+
+    """
+    import imp
+    has3147 = hasattr(imp, 'get_tag')
+    if has3147:
+        return imp.cache_from_source(path)
+    else:
+        return simple_pyc_file_from_path(path)
+
+
+def load_python_file(dir_, filename):
+    """Load a file from the given path as a Python module."""
+
+    module_id = re.sub(r'\W', "_", filename)
+    path = os.path.join(dir_, filename)
+    _, ext = os.path.splitext(filename)
+    if ext == ".py":
+        if os.path.exists(path):
+            module = load_module_py(module_id, path)
+        elif os.path.exists(simple_pyc_file_from_path(path)):
+            # look for sourceless load
+            module = load_module_pyc(
+                module_id, simple_pyc_file_from_path(path))
+        else:
+            raise ImportError("Can't find Python file %s" % path)
+    elif ext in (".pyc", ".pyo"):
+        module = load_module_pyc(module_id, path)
+    del sys.modules[module_id]
+    return module
diff --git a/alembic/util/sqla_compat.py b/alembic/util/sqla_compat.py
new file mode 100644
index 0000000..41badd4
--- /dev/null
+++ b/alembic/util/sqla_compat.py
@@ -0,0 +1,24 @@
+import re
+from sqlalchemy import __version__
+
+
+def _safe_int(value):
+    try:
+        return int(value)
+    except:
+        return value
+_vers = tuple(
+    [_safe_int(x) for x in re.findall(r'(\d+|[abc]\d)', __version__)])
+sqla_07 = _vers > (0, 7, 2)
+sqla_079 = _vers >= (0, 7, 9)
+sqla_08 = _vers >= (0, 8, 0)
+sqla_083 = _vers >= (0, 8, 3)
+sqla_084 = _vers >= (0, 8, 4)
+sqla_09 = _vers >= (0, 9, 0)
+sqla_092 = _vers >= (0, 9, 2)
+sqla_094 = _vers >= (0, 9, 4)
+sqla_094 = _vers >= (0, 9, 4)
+sqla_099 = _vers >= (0, 9, 9)
+sqla_100 = _vers >= (1, 0, 0)
+sqla_105 = _vers >= (1, 0, 5)
+
diff --git a/docs/build/api.rst b/docs/build/api.rst
index fea4e14..a22d333 100644
--- a/docs/build/api.rst
+++ b/docs/build/api.rst
@@ -56,13 +56,13 @@ current :class:`.EnvironmentContext` in use.
 In particular, the key method used within ``env.py`` is :meth:`.EnvironmentContext.configure`,
 which establishes all the details about how the database will be accessed.
 
-.. automodule:: alembic.environment
+.. automodule:: alembic.runtime.environment
     :members:
 
 The Migration Context
 =====================
 
-.. automodule:: alembic.migration
+.. automodule:: alembic.runtime.migration
     :members:
 
 The Operations Object
@@ -151,7 +151,7 @@ Revision
 The :class:`.RevisionMap` object serves as the basis for revision
 management, used exclusively by :class:`.ScriptDirectory`.
 
-.. automodule:: alembic.revision
+.. automodule:: alembic.script.revision
     :members:
 
 Autogeneration
diff --git a/docs/build/ops.rst b/docs/build/ops.rst
index 1df9d27..b4838aa 100644
--- a/docs/build/ops.rst
+++ b/docs/build/ops.rst
@@ -7,8 +7,8 @@ Operation Reference
 This file provides documentation on Alembic migration directives.
 
 The directives here are used within user-defined migration files,
-within the ``upgrade()`` and ``downgrade()`` functions, as well as 
-any functions further invoked by those.  
+within the ``upgrade()`` and ``downgrade()`` functions, as well as
+any functions further invoked by those.
 
 All directives exist as methods on a class called :class:`.Operations`.
 When migration scripts are run, this object is made available
@@ -19,11 +19,11 @@ with individual proxies for each method on :class:`.Operations`,
 so symbols can be imported safely from the ``alembic.op`` namespace.
 
 A key design philosophy to the :mod:`alembic.operations` methods is that
-to the greatest degree possible, they internally generate the 
+to the greatest degree possible, they internally generate the
 appropriate SQLAlchemy metadata, typically involving
 :class:`~sqlalchemy.schema.Table` and :class:`~sqlalchemy.schema.Constraint`
-objects.  This so that migration instructions can be 
-given in terms of just the string names and/or flags involved.   
+objects.  This so that migration instructions can be
+given in terms of just the string names and/or flags involved.
 The exceptions to this
 rule include the :meth:`~.Operations.add_column` and :meth:`~.Operations.create_table`
 directives, which require full :class:`~sqlalchemy.schema.Column`
diff --git a/tests/test_autogen_render.py b/tests/test_autogen_render.py
index 52f3601..32975f0 100644
--- a/tests/test_autogen_render.py
+++ b/tests/test_autogen_render.py
@@ -16,7 +16,8 @@ from sqlalchemy.sql import and_, column, literal_column, false
 
 from alembic.testing.mock import patch
 
-from alembic import autogenerate, util, compat
+from alembic import autogenerate, util
+from alembic.util import compat
 from alembic.testing import eq_, eq_ignore_whitespace, config
 
 from alembic.testing.fixtures import op_fixture
diff --git a/tests/test_batch.py b/tests/test_batch.py
index a498c36..c827ac4 100644
--- a/tests/test_batch.py
+++ b/tests/test_batch.py
@@ -1,15 +1,13 @@
 from contextlib import contextmanager
 import re
 
-import io
-
 from alembic.testing import exclusions
 from alembic.testing import TestBase, eq_, config
 from alembic.testing.fixtures import op_fixture
 from alembic.testing import mock
 from alembic.operations import Operations
-from alembic.batch import ApplyBatchImpl
-from alembic.migration import MigrationContext
+from alembic.operations.batch import ApplyBatchImpl
+from alembic.runtime.migration import MigrationContext
 
 
 from sqlalchemy import Integer, Table, Column, String, MetaData, ForeignKey, \
@@ -503,7 +501,7 @@ class BatchAPITest(TestBase):
         batch = op.batch_alter_table(
             'tname', recreate='never', schema=schema).__enter__()
 
-        with mock.patch("alembic.operations.sa_schema") as mock_schema:
+        with mock.patch("alembic.operations.base.sa_schema") as mock_schema:
             yield batch
         batch.impl.flush()
         self.mock_schema = mock_schema
diff --git a/tests/test_config.py b/tests/test_config.py
index db37456..da0b413 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -1,9 +1,8 @@
 #!coding: utf-8
 
-import os
-import tempfile
 
-from alembic import config, util, compat
+from alembic import config, util
+from alembic.util import compat
 from alembic.migration import MigrationContext
 from alembic.operations import Operations
 from alembic.script import ScriptDirectory
diff --git a/tests/test_op.py b/tests/test_op.py
index 7d5f83e..5be9aa8 100644
--- a/tests/test_op.py
+++ b/tests/test_op.py
@@ -524,7 +524,8 @@ class OpTest(TestBase):
     def test_add_foreign_key_dialect_kw(self):
         op_fixture()
         with mock.patch(
-                "alembic.operations.sa_schema.ForeignKeyConstraint") as fkc:
+                "alembic.operations.base.sa_schema.ForeignKeyConstraint"
+        ) as fkc:
             op.create_foreign_key('fk_test', 't1', 't2',
                                   ['foo', 'bar'], ['bat', 'hoho'],
                                   foobar_arg='xyz')
diff --git a/tests/test_revision.py b/tests/test_revision.py
index d73316d..0a515de 100644
--- a/tests/test_revision.py
+++ b/tests/test_revision.py
@@ -1,6 +1,6 @@
 from alembic.testing.fixtures import TestBase
 from alembic.testing import eq_, assert_raises_message
-from alembic.revision import RevisionMap, Revision, MultipleHeads, \
+from alembic.script.revision import RevisionMap, Revision, MultipleHeads, \
     RevisionError
 
 
diff --git a/tests/test_script_consumption.py b/tests/test_script_consumption.py
index 11b8080..c2eef0a 100644
--- a/tests/test_script_consumption.py
+++ b/tests/test_script_consumption.py
@@ -3,7 +3,8 @@
 import os
 import re
 
-from alembic import command, util, compat
+from alembic import command, util
+from alembic.util import compat
 from alembic.script import ScriptDirectory, Script
 from alembic.testing.env import clear_staging_env, staging_env, \
     _sqlite_testing_config, write_script, _sqlite_file_db, \